Summary of Significant Accounting Policies - Basis of Consolidation (Narrative) (Details)	Jun. 30, 2026	Dec. 31, 2025	Jun. 30, 2025
Marketwise, LLC
Significant Accounting Policies [Line Items]
Ownership percentage in subsidiary	17.00%	15.20%	14.80%

The parent entity's interest in net assets of the subsidiary, expressed as a percentage.

No definition available.

Name:	us-gaap_MinorityInterestOwnershipPercentageByParent
Namespace Prefix:	us-gaap_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	instant